Trouble Shooting Seed Starting Issues
Once your seeds have sprouted and started growing, providing enough light is key to keep your seedlings compact and growing strong. If you look closely in the photo above you can see my tomato seedlings have quickly outgrown the basil seedlings right next to them and have gotten a bit stretched. This was caused by having my light too far away from the flat. To help fix this issue I move the light about 2-4” from the tray and they quickly slowed their growth.To help keep the plants compact I also changed the timer on my lights so they were on for a minimum of 14 hours instead of the 12 I had with the rest of my tropical plants. If you continue to have issues with seedlings stretching after moving them closer to the light you can also add a fan blowing across the tray. That will slow the growth as the seedling acclimate to the air flow.
It’s amazing how quickly those seedlings can grow and change. The picture above is the same tomato seedlings less than two weeks later. Once the seedlings had developed their first set of true leaves I transplanted them from the Jiffy pellets up to a larger tray. The tomatoes are the fastest growing of my seedlings and needed more room for their roots to grow. It’s also easier to keep the light where I need it for the rest of my plants by moving the tallest plants to their own tray. When you transplant seedlings always hold them by leaves or in my case the peat pellets, never hold them by the stem. A seedling can regrow leaves if they are torn off on accident but it will not regrow if the stem is broken. Most vegetables you will plant at the same depth they were growing before. I did plant my tomato seedlings a bit deeper than the peat pellet to compensate for the stretching but tomatoes will root along the stem where other plants will not.
Once I transplanted my tomatoes and watered them in well I then fertilized the tomatoes and lettuce bowls because I was seeing some yellowing the leaves. I used a soluble houseplant fertilizer at the recommended rate on the label. I will continue to fertilize these little babies every week or two as needed. Ideally my transplants should be dark green in color with short and sturdy stems. If my seedlings continue to have a yellow tint or develop a purple hue I will need to change my fertilizer schedule and fertilize more frequently. It is very important to follow the recommended rates for seedlings because they can be delicate and easily damaged if you overfertilize them. The rest of the seedlings will have to wait for fertilizer till after they are transplanted.
Have questions? Contact our office where our Horticulture Extension Agent will assist you with questions.
Phone: (316) 321-9660
Email: callae@ksu.edu